U.S. patent application number 09/880010 was filed with the patent office on 2003-01-09 for water-enhanced production of 1,1,1,3,3,-pentachloropropane.
Invention is credited to Branam, Lloyd B..
Application Number | 20030009066 09/880010 |
Document ID | / |
Family ID | 25375335 |
Filed Date | 2003-01-09 |
United States Patent
Application |
20030009066 |
Kind Code |
A1 |
Branam, Lloyd B. |
January 9, 2003 |
WATER-ENHANCED PRODUCTION OF 1,1,1,3,3,-PENTACHLOROPROPANE
Abstract
A process is provided by which addition of water is used to
enhance the production of any hydrochlorocarbon feedstock through
the use of Kharasch chemistry, i.e. the combination of a
polychlorinated alkane with an olefin to produce a chlorinated or
hydrochlorinated alkane with the use of a transition metal compound
in homogeneous solution as catalyst. Preferably, water is added to
increase the production of 1,1,1,3,3-pentachloropropane by the
reaction of carbon tetrachloride and vinyl chloride in the presence
of a catalyst mixture of organo phosphate solvent, iron metal and
ferric chloride.
Inventors: |
Branam, Lloyd B.; (Wichita,
KS) |
Correspondence
Address: |
Teresa Stanek Rea
BURNS, DOANE, SWECKER & MATHIS, L.L.P.
P.O. Box 1404
Alexandria
VA
22313-1404
US
|
Family ID: |
25375335 |
Appl. No.: |
09/880010 |
Filed: |
June 14, 2001 |
Current U.S.
Class: |
570/257 |
Current CPC
Class: |
C07C 17/278 20130101;
C07C 17/278 20130101; C07C 17/275 20130101; C07C 19/01
20130101 |
Class at
Publication: |
570/257 |
International
Class: |
C07C 017/266 |
Claims
What is claimed is:
1. A process for the production of 1,1,1,3,3-pentachloropropane by
the reaction of carbon tetra-chloride and vinyl chloride in a
reactor, wherein water is added in an amount sufficient to increase
the rate of the reaction.
2. The process according to claim 1, wherein water is added at an
amount ranging from about 10 ppm to about 50 ppm based on the total
weight of the reactants.
3. The process according to claim 1, wherein the water is added
continuously or on a periodic basis.
4. The process according to claim 1, wherein the water is added
directly to the reactor containing the carbon tetrachloride and
vinyl chloride.
5. The process according to claim 1, wherein the water is added to
the carbon tetrachloride or vinyl chloride prior to their addition
to the reactor.
6. The process according to claim 1, wherein the reactor contains a
catalyst mixture comprising organo phosphate solvent, iron metal
and ferric chloride.
7. The process according to claim 6, wherein the organo phosphate
solvent is tributyl phosphate.
8. A process for the production of a chlorinated or
hydrochlorinated alkane by the reaction of a polychlorinated alkane
and an olefin in a reactor, wherein water is added in an amount
sufficient to increase the rate of the reaction.
9. The process according to claim 8, wherein water is added at an
amount ranging from about 10 ppm to about 50 ppm based on the total
weight of the reactants.
10. The process according to claim 8, wherein the water is added
continuously or on a periodic basis.
11. The process according to claim 8, wherein the water is added
directly to the reactor containing the polychlorinated alkane and
olefin.
12. The process according to claim 8, wherein the water is added to
the polychlorinated alkane or olefin carbon prior to their addition
to the reactor.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a process for the
manufacture of 1,1,1,3,3-pentachloropropane.
[0003] 2. Description of the Related Art
[0004] The Montreal Protocol of 1987 placed a ban on certain
substances that deplete the ozone layer, especially
chlorofluorocarbons (CFC's). To hasten the elimination of CFC
production and use, the Protocol allowed for certain fluorocarbon
products (HCFC's) to be used as "bridge replacements." Although
these bridge replacements are considerably more ozone friendly than
CFC'S, they are intended to be transitional and not permanent
replacements. Fluorocarbon producers are actively pursuing
replacement candidates known as "third generation fluorocarbons."
These third genera-tion fluorocarbons will require
hydrochlorocarbon feedstocks.
[0005] The second largest U.S. fluorochemical end-use market, next
to refrigeration, is for blowing agents utilized in the manufacture
of various synthetic plastic formed products. CFC-1 1 was the
dominant product in this market, however, it has been replaced by
the bridge-fluorocarbon HCFC-141b. Because foam manufacturers must
transition away from HCFC-141b by 2003, new third generation
fluorocarbon products must be developed and commercialized.
[0006] Several fluorochemical producers have targeted fluorocarbon
1,1,1,3,3-pentafluoropropane, utilizing
1,1,1,3,3-pentachloropropane as the hydrochlorocarbon feedstock, as
the primary replacement product for foam blowing applications.
Zil'bennan et.al. ("Synthesis of liquid telomers of vinyl chloride
with carbon tetrachloride", J. Org. Chem. USSR (English Transl.),
3:2101-2105,1967) prepared 1,1,1,3,3-pentachloropropan- e in a 58%
yield by the reaction of carbon tetrachloride and vinyl chloride
using ferrous chloride tetrahydrate in isopropanol. In addition,
Kotora et.al ("Addition of tetrachloromethane to halogenated
ethenes catalyzed by transition metal complexes", J. Mol. Catal.,
77(1):51-60,1992) prepared 1,1,1,3,3-pentachloropropane in high
yields using either CuCl/C.sub.4H.sub.9NH.sub.2 or
Ru(Ph.sub.3P).sub.3.
[0007] European Patent Application No.131561 describes a very
general process for the addition of a haloalkane to an alkene or
alkyne compound in the presence of iron metal and a phosphorus (V)
compound. While EP 131561 is very general in nature, several
examples are set forth on the batch reaction of ethylene and carbon
tetrachloride to produce 1,1,1,3-tetrachloropropane. However, EP
131561 does mention a wide variety of olefins and alkynes,
including vinyl halides. EP 131561 also mentions that the batch
process could be made continuous, but does not include any
specifics on how this would be carried out.
[0008] Despite the known processes, improvements are needed in the
manufacture of 1,1,1,3,3-pentachloro-propane. The present invention
is directed to such an improved process. More particularly, the
present invention relates to the addition of water to enhance
production of 1,1,1,3,3-pentachloropropane.
OBJECTS AND SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide an
improved process for the production of chlorinated or
hydrochlorinated alkanes. More particularly, a process is provided
by which addition of water is used to enhance the production of any
hydrochlorocarbon feedstock through the use of Kharasch chemistry,
i.e., the combination of a polychlorinated alkane with an olefin to
produce a chlorinated or hydrochlorinated alkane.
[0010] In one aspect, the invention provides a process for the
production of a chlorinated or hydrochlorinated alkane by the
reaction of a polychlorinated alkane and an olefin in a reactor,
wherein water is added in an amount sufficient to increase the rate
of the reaction.
[0011] In another aspect, the invention provides a process for the
production of 1,1,1,3,3-pentachloropropane by the reaction of
carbon tetrachloride and vinyl chloride in a reactor, wherein water
is added in an amount sufficient to increase the rate of the
reaction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates the effect of water on
1,1,1,3,3-pentachloroprop- ane production as a function of pressure
versus grams of vinyl chloride fed.
[0013] FIG. 2 illustrates the residual vinyl chloride after water
addition in a process for making 1,1,1,3,3-pentachloropropane.
[0014] FIG. 3 illustrates the hexachloroethylene concentration in
reactor effluent after water addition in a process for making
1,1,1,3,3-pentachloropropane.
[0015] FIG. 4 illustrates the chlorinated pentane selectivity after
water addition in a process for making
1,1,1,3,3-pentachloropropane.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] The present invention generally relates to a process for the
manufacture of the hydrochlorocarbon 1,1,1,3,3-pentachloropropane.
More particularly, the present invention provides for the
manufacture of 1,1,1,3,3-pentachloropropane by the reaction of
carbon tetrachloride with vinyl chloride in the presence of
tributyl phosphate solvent and a catalyst comprising metallic iron,
ferrous chloride or ferric chloride and mixtures thereof, and
enhanced production of 1,1,1,3,3-pentachloropro- pane by such a
process upon addition of small amounts of water.
[0017] The present invention makes use of Kharasch chemistry for
making 1,1,1,3,3-pentachloropropane (Kharasch et al, Science,
102:128, 1945). This chemistry involves combining a polychlorinated
alkane with an olefin to produce a chlorinated or hydrochlorinated
alkane having the chlorine in precise locations. Transition metal
compounds in homogeneous solution are typically used as catalysts.
For example, carbon tetrachloride may be added to ethylene in the
presence of dissolved ferrous chloride and a cosolvent to make
1,1,1,3-tetrachloropropane with excellent selectivity.
[0018] In the present invention, the Kharasch reaction is as
follows: 1
[0019] Thus, the present invention relates to the production or
manufacture of 1,1,1,3,3-pentachloropropane by the liquid phase
reaction of carbon tetrachloride with vinyl chloride. The catalyst
is a mixture of ferrous and ferric chloride, with the ferrous
chloride being generated by the reaction of ferric chloride and
metallic iron in the presence of an organo phosphate solvent, such
as tributyl phosphate.
[0020] The ferric/ferrous chloride catalyzed
1,1,1,3,3-pentachloropropane production is comprised of three
processing steps: reaction, catalyst recovery, and purification.
The reaction takes place in the presence of a ferric/ferrous
chloride catalyst dissolved in organo phosphate solvent. Tributyl
phosphate is the preferred organo phosphate solvent. The reaction
is a Kharasch addition reaction in which a halogenated compound is
added to the double bond of another compound. In this case, carbon
tetrachloride is reacted with vinyl chloride to produce
1,1,1,3,3-pentachloropropane.
[0021] It has been observed that, at times, the reaction for
production of 1,1,1,3,3-pentachloropropane is sluggish. During
these sluggish periods, the reaction rates are slowed and the
selectivity to desired products suffers. It has been found that
addition of a small amount of water to the reactor results in a
dramatic increase in the reaction rate of vinyl chloride and carbon
tetrachloride and eliminates erratic operation. Water addition
results in an exothermic reaction with good feed conversions and
completion of the run with pressures well below the limitations of
the production equipment.
[0022] This solution to the problem of sluggish production of
1,1,1,3,3-pentachloropropane is counter-intuitive since, prior to
the present invention, the conventional wisdom has been to avoid
addition of water during production of chlorinated hydrocarbons due
to the possibility of corrosion. The ferric chloride used in the
reaction would normally be expected to be deactivated by water and,
thus, one would typically keep the feedstocks as dry as
possible.
[0023] Water in any amount which enhances the rate of reaction of
carbon tetrachloride and vinyl chloride to produce
1,1,1,3,3-pentachloropropane is within the scope of the present
invention. Water is added in an amount ranging from about 1 ppm to
about 500 ppm based on the total weight of the reactants. More
preferably, a range of 10 ppm to about 50 ppm of water based on the
total weight of the reactants is used. Water can be added to the
reactor periodically or in a continuous fashion.
[0024] More generally, water addition can be used to enhance the
production of any hydrochlorocarbon feedstock through the use of
Kharasch chemistry, i.e., the combination of a polychlorinated
alkane with an olefin to produce a chlorinated or hydrochlorinated
alkane with the use of a transition metal compound in homogeneous
solution as catalyst.
EXAMPLE 1
[0025] Laboratory Reactor Setup
[0026] A 1-liter glass reactor from ACE Glass capable of handling
50 psig was setup in the laboratory. The reactor was fitted with an
externally driven stirrer, a vent going to a manifold containing an
emergency relief valve and rupture disk (50 psig), a thermowell,
sample valve, and vinyl chloride addition tube extending below the
reactor liquid level. The reactor was operated as a semi-batch
system with all the ingredients (reactants and catalyst mixture)
being added to the reactor at the beginning of a run except for the
vinyl chloride. The vinyl chloride was metered continuously into
the reactor through an FMI pump at a rate of approximately 1
gram/minute. For each run, the reactor was charged with iron (Fe)
powder, ferric chloride (FeCl.sub.3), carbon tetrachloride
(CCl.sub.4), and tributyl phosphate (TBP). Subsequent runs also
included a charge of 1,1,1,3,3-pentachloropropane pilot plant
flasher bottoms in order to simulate anticipated plant reactor
conditions. The solution was mixed at 250 rpm and heated to
60.degree. C. Initially, vinyl chloride (10 grams) was added to the
mixture to prevent undesirable side reactions as the solution
reached reaction temperature. When the solution reached the desired
operating temperature of approximately 100.degree. C., the vinyl
chloride feed was introduced at a rate of 1 gm/minute. The
temperature was controlled at 104.degree. C. during the run. The
vinyl chloride was fed from a reservoir on a balance in order to
accurately measure the amount added during the run. The
experimental run was allowed to operate an additional hour after
the vinyl chloride addition was complete.
EXAMPLE 2
[0027] Baseline Runs, No Water Addition
[0028] The initial shake down runs were conducted with the
following materials charged to or being fed to the reactor during
the run.
1 Weight Molar Ratio to Compound Weight (gms) Percent Moles Vinyl
chloride Vinyl chloride 166.0 19.53 2.656 CCl.sub.4 657.0 77.31
4.272 1.61 TBP 17.43 2.05 0.065 0.025 FeCl.sub.3 9.00 1.06 0.055
0.021 Fe .45 0.53 0.01 0.003
[0029] The CCl.sub.4, TBP, FeCl.sub.3, and Fe were added to the
reactor, which was stirred at 250 RPM. After the temperature
reached approximately 60.degree. C., 10 grams of vinyl chloride
were added to prevent unwanted side reactions as the solution
approached operating temperature (104.degree. C.). The remaining
vinyl chloride was metered into the solution at approximately 1
gram/minute until the total weight desired for the experimental run
had been added. The initial runs had to be stopped several times
due to excessive pressure in the reactor and the run was terminated
without being able to feed the desired amount of vinyl chloride.
The rupture disk was set at 50 psig and the vinyl chloride addition
was stopped when the pressure reached 45 psig. The next few runs
were modified to try to increase the reaction rate and thus
decrease the pressure of the system due to unreacted vinyl
chloride. The modifications to the system included:
[0030] (1) Slower addition of vinyl chloride;
[0031] The vinyl chloride was added at a rate of approximately 0.7
grams/minute;
[0032] (2) Higher temperature (115.degree. C.);
[0033] (3) Additional iron powder;
[0034] The amount of iron powder added to the reactor was doubled
from the baseline amount;
[0035] (4) Addition of ferrous chloride in addition to the ferric
chloride and iron powder;
[0036] (5) Addition of 1,1,1,3,3 pentachloropropane to increase the
vinyl chloride solubility;
[0037] 220 grams of pure 1,1,1,3,3 pentachloropropane was added to
the reactor to adsorb more unreacted vinyl chloride and lower the
vapor pressure of the reactant mixture which results in lower
pressure in the reactor;
[0038] (6) Additional TBP;
[0039] The TBP was increased from 17.4 grams to 25 grams.
[0040] In every case, the experimental run had to be prematurely
terminated due to excessive pressure.
EXAMPLE 3
[0041] Addition of Water
[0042] A run was completed with the addition of 20 micro-liters of
water using the same feed material concentrations as a previous
run, which had to be terminated due to excessive pressure:
2 Weight Weight Molar Ratio to Vinyl Compound (gms) Percent Moles
Chloride Vinyl Chloride 166.0 19.35 2.656 CCl.sub.4 657.0 76.58
4.272 1.61 TBP 25.0 2.91 0.094 0.035 FeCl.sub.3 9.00 1.05 0.055
0.021 Fe 0.9 0.105 0.016 0.006
[0043] During this run, as the reaction temperature approached
104.degree. C., there was a large exothermic reaction where the
temperature increased 10-20.degree. C. This was very surprising
because the amount of water added was only an increase of 23-ppm in
the system. In all the previous runs, no exothermic reaction was
noted. This addition of a small amount of water also allowed this
run to go to completion without exceeding the pressure limitations
of the glass reactor.
EXAMPLE 4
[0044] Addition of Water
[0045] Example 3 was repeated using 10 micro-liters of water
instead of 20 micro-liters with the same results. There was an
exothermic reaction and the vinyl chloride was fed to the system at
the desired rate and concentration without exceeding the pressure
limitations of the glass reactor. Several attempts were made to
control the exothermic reaction. Modification in the operating
procedure included heating the mixture to 60.degree. C. (versus
100.degree. C.) and adding 10 grams of vinyl chloride, addition of
1,1,1,3,3-pentachloropropane to allow dilution of the reactants,
and slower heating of the reactant mixture. The addition of 220
grams 1,1,1,3,3-pentachloropropane as a diluent was the most
helpful in controlling the exothermic reaction.
EXAMPLE 5
[0046] Water Addition with Pilot Plant Flasher Bottoms
[0047] An experimental run was conducted whereby 20 micro-liters of
water was added to the laboratory reactor after it had been charged
with flasher bottoms from the pilot plant reactor. The flasher
bottoms material was removed from the pilot plant because of very
poor reaction kinetics and overall poor operation. The feed and
catalyst concentrations for the run were the same as Example 3
except that 220 grams of flasher bottoms were added to the reactor.
The reactor ran well and all the vinyl chloride was added at the
appropriate rate (1 gram/minute).
[0048] This run was repeated using the same conditions without the
addition of water. After 37 grams of vinyl chloride out of the
target total of 166 grams had been added, the pressure had
increased to 45 psig and the vinyl chloride feed was shut off and
the run stopped. Twenty micro-liters of water were added to the
vinyl chloride feed line and, as the pressure allowed, the vinyl
chloride was fed slowly to the system. An exothermic reaction
occurred after some of the water and fresh vinyl chloride had
entered the reactor. The pressure began to drop which allowed the
vinyl chloride to be added to the system at the normal rate of 1
gram/minute. The effect of the water addition both before the start
of the run with the flasher bottoms and during the run is shown in
FIG. 1.
[0049] As noted in FIG. 1, the run with 20 micro-liters of water
added at the start of the run had a pressure of approximately 30
psig after 25 grams of vinyl chloride had been added. This pressure
dropped to 22-23 psig by the end of the run as the vinyl chloride
and the CCl.sub.4 reacted. The run without 20 micro-liters of water
had a pressure of approximately 40 psig after 25 grams of vinyl
chloride had been fed. This run could not continue due to excessive
pressure. After the addition of 20 micro-liters of water in the
vinyl chloride feed line, the run was allowed to continue and the
pressure profile looked very similar to the previous run, operating
at 22-23 psig.
EXAMPLE 6
[0050] Pilot Plant Run with Water Addition
[0051] The pilot plant process for producing
1,1,1,3,3-pentachloropropane had operated poorly for a significant
period of time. Reaction rates were low and operating pressures
high. The poor performance was attributed to operating with new
batches of CCl.sub.4 and TBP. The mixture of TBP and CCl.sub.4 used
in the catalyst addition system was spiked with water (65 ppm based
on total reactants) and fed to the pilot plant reactor. The vent
flows from the flash tower, which is mainly vinyl chloride,
decreased dramatically during the next 4-6 hours. Also the vinyl
chloride concentration in the reactor effluent decreased from 1.7
to 0.5 percent overnight. In addition to the decrease in vinyl
chloride concentration (FIG. 2), the concentrations of waste
by-products (hexachlorothane (FIG. 3) and chlorinated pentanes
(FIG. 4) were also decreased.
[0052] While the invention has been described in terms of preferred
embodiments, the skilled artisan will appreciate that various
modifications, substitutions, omissions and changes may be made
without departing from the spirit thereof. Accordingly, it is
intended that the scope of the present invention be limited solely
by the scope of the following claims, including equivalents
thereof.
* * * * *